A variety of apparatuses and processes have heretofore been used or proposed for use in the thermal pyrolysis and/or gasification of carbonaceous materials for producing gaseous fuels, activated chars, extraction of valuable hydrocarbon constituents and the like. Conventionally, the carbonaceous material in a particulated form is introduced into a retort or reaction chamber in which it is heated to an elevated temperature while in a controlled atmosphere for a period of time sufficient to effect a thermal degradation or pyrolysis of the feed material accompanied by a liberation of volatile gaseous constituents and gaseous pyrolysis by-products. The carbonaceous feed material can comprise materials of vegetable origin including, for example, tree bark, wood chips, sawdust, rice hulls, nutsheels, corn husks, as well as vegetable derivatives, such as peat, lignite, coal, and materials containing such carbonaceous substances, such as oil shale and tar sands.
A continuing problem associated with processes of the foregoing type has been the tendency of the gaseous pyrolysis products produced to deposit on the surfaces of the carbonized product produced, as well as on the surfaces of the equipment, reducing the efficiency of the pyrolysis reaction and also necessitating frequenct shut-downs to remove the carbonaceous deposit from the walls of the retort and associated gas passages. In the manufacture of activated char or carbon employing thermal pyrolysis reactors of the foregoing type, the redeposition of the carbonaceous residues on the surfaces of the char produced substantially reduces the activity of the activated carbon product normally necessitating supplemental activation treatments. The deposition of carbonaceous residues on the equipment surfaces in the form of tars and coke obstructs the uniform flow of the feed material and an efficient removal of the gaseous by-products frequently causing localized hot spots, causing an overcracking or excessive thermal degradation of the gaseous by-products, which still further aggravates the formation and deposition of carbonaceous residues.
In the prior copending application, a process and apparatus is disclosed which overcomes many of the problems associated with prior art apparatuses and techniques by providing a pyrolysis reactor system in which improved control of the uniformity of heating of the carbonaceous feed material is achieved and wherein the deposition of carbonaceous residue on equipment surfaces and on the carbonized product itself is substantially reduced. In the adaptation of the apparatus and process for making activated carbon, a continuous production of activated carbon having high adsorptive capacity is provided without requiring further activation treatments as is required in accordance with prior art techniques. The apparatus of the present invention provides similar benefits as are achieved in accordance with the prior invention and further provide for an improved reactor apparatus which is more compact, more efficient and of increased versatility.